


Day Ten

by FellQueen (Nikasha)



Series: Kinktober 2019 [10]
Category: Undertale (Video Game)
Genre: Come Inflation, M/M, Sansgore, Size Difference, Size Kink
Language: English
Status: Completed
Published: 2019-10-11
Updated: 2019-10-11
Packaged: 2020-12-09 00:15:41
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,968
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20985644
Author URL: https://archiveofourown.org/users/Nikasha/pseuds/FellQueen
Summary: Day TenPrompt: Size DifferencePairing: Sansgore (Sans/Asgore)





	Day Ten

**Author's Note:**

> Is this ship also called Fluffypuns? Because if not, that’s a real shame.
> 
> This chapter be posted late af. I’m sleepy.

Sans stared at the ceiling above him, trying real hard not to think about what he was doing. The sheets underneath him were ridiculously soft, a surprising comfort. Normally the king tended to avoid rewarding himself in any way.  
He supposed it wasn’t so different from what was happening right now. Sure, Sans had asked <s>begged</s> but that didn’t mean Asgore was obligated to go through with it. He had to be getting something out of this, too.  
A paw touched his bare femur and he tried not to flinch. He wasn’t scared by any means, but stars, his hand was warm. And soft.  
Asgore opened his mouth to speak, then sighed out a heavy breath. “You are free to change your mind at any time,” he said in that deep, disturbingly fathering voice.  
Yeah, no, Sans needed to shut that down pronto. He sat up, tangling his fingers through Asgore’s chestfur. Also soft. “Nah, buddy, I’m not changing my mind,” he purred out, eyelights dimming to a softer glow. “I want that king-sized dick in me.”  
Asgore smiled and it was almost sad. “Of course.”  
Sans could have waxed poetic about it, but the king derailed his train of thought by picking him up by the hips and turning. Asgore laid back on the bed, Sans now kind of straddling his waist. It was difficult to straddle something so wide.  
Sans swallowed.  
Gentle hands gripped his hips and Asgore laid there patiently, letting Sans adjust to the idea. It was suddenly clear why he had rolled them; he was huge and probably heavy. And Sans had an amazing one HP. Stellar.  
Sans resolved to get them switched back at some point, but for now he let his magic settle in his pelvis. It fought him a little, not really interested in forming quite yet, but Sans gave it a metaphorical shove and down it went.  
As the blue ecto settled into his place, Asgore pushed on Sans’s upper back. Confused, but willing, he followed the nudging until he was laying down on him, phalanges tangling into fur.  
Asgore watched him through almost sleepy eyes as he reached around behind Sans and found his entrance, first teasing his fingers along the outside, then sliding one in.  
Sans’s breath hitched. Even his fingers were large, and just one of them was fitting into him snugly. He was frozen for a moment, but when he noticed Asgore watching him, he grit his teeth and pushed back onto his digit.  
He closed his eyes. It felt huge inside of him, reaching places that rightfully shouldn’t be touched by just one damn finger. Asgore curled it and Sans hissed, jolting.  
A second finger was introduced and Sans was already panting. It burned, stretching him out like some people’s dicks would. He rutted back, but Asgore’s free hand on his hip stopped him. Sans huffed quietly, forced to let his magic adjust to it.  
When the king started moving his fingers again, it was accompanied by a slick noise. Sans hid his face in Asgore’s chest, embarrassed by the sounds of his arousal. His hand moved faster, then curled and spread. Sans almost stopped breathing, mildly horrified by how empty he felt after that.  
His wetness was sliding down his cunt to drench Asgore’s belly, and that was sending darts of uncomfortable heat between his legs and to his face.  
A third finger. Sans actually whined this time and urgently pushed back against the insertion, rolling his hips.  
Asgore let him for a bit before thrusting his fingers harshly into Sans. “Like that?” he asked quietly, his voice pitched even deeper with lust.  
Sans moaned, tugging at the fur in his hands desperately. Asgore’s hand smacked into his tailbone each time it was thrust inward until Sans could feel Asgore’s fur was flat and wet. He exhaled shakily.  
The hand on his hip moved. The king reached between them and brushed against Sans’s clit once, twice. Sans broke, shuddering as he came over the fingers knuckle-deep in his cunt.  
Panting, Sans met Asgore’s gaze. “Didn’t have to do that.”  
“I would rather not split you in half,” he responded amicably.  
Sans snorted tiredly. “You won’t. I have tricks up my sleeve, fluffybuns.”  
“Of course.” Asgore smiled again.  
Sans ignored the edge of disbelief in it. He sat up and turned, looking at the cock resting on Asgore’s pelvis behind him. “Not into this, majesty?”  
Asgore chuckled and the vibrations rolled through Sans’s sensitive clit, making him jump. “I apologize.”  
“Nah, I got this.” Sans turned around completely, facing away. He took Asgore in hand, impressed despite himself when he couldn’t remotely close his hand around the girth. He certainly wasn’t getting that in his mouth.  
He leaned forward and drew his tongue up the side, earning a groan. A couple more licks, hand sliding slowly along the length, and he moved to suckle at the head, sockets lidding at the heavy musk that came off of him. He drew his tongue over Asgore’s slit and felt the king’s stomach tense under him, fighting not to thrust upwards and unbalance Sans. “Gee, thanks,” he commented idly.  
Asgore ignored him.  
Alternating between licks and sucking, then small gentle nips that had Asgore shaking, Sans got him erect. He sat back and contemplated how that was going to fit in his pussy. He wasn’t even sure it would fit in his pelvis.  
Asgore’s hand brushed along his cheekbone. “Turn around.”  
Well, who was he to disobey the king of monsters? Sans turned around. Asgore picked him up by the hips again, settling him over his cock. Sans could feel the heat of him at his entrance and inhaled sharply.  
Asgore started to lower him. It was painfully slow, and once Sans had his feet on the bed, the king let Sans take back control.  
Still, it was incredible. His magic was forced to adjust itself by alternate means, changing its form instead of just stretching. Sans could have sworn he heard his pelvis creak in protest. But he managed. And when he was sitting with their pelvises resting together, he moaned loud, putting a hand on his abdomen that had melded into place. It felt like Asgore was in his throat.  
The king was making huffing noises through his nose, clearly as painfully turned on as Sans. But he didn’t rush it, didn’t ask. He just waited.  
Sans was unfortunately grateful for the reprieve. But once he was ready, he started moving like there was nothing else left for him but Asgore’s cock.  
Sans gasped and cried out, full to bursting and feeling the pressure of him on all of his walls. He braced his hands on Asgore’s stomach, whining.  
Asgore reached up and gently ran his paws over Sans’s ribcage, squeezing at the middle, then moving to reach around and pinch his tailbone. Sans bucked, startled, and keened. “So...much,” he gasped out.  
Asgore traced himself through Sans’s ecto. Even such a gentle king seemed pleased by the wreck he was creating of Sans. “You’re doing so well,” he murmured.  
Sans flinched. Wetness seeped out of him in response and he tightened down involuntarily.  
Asgore smiled. “You are a good judge,” he said quietly. “And good in bed. And a good subject.”  
Sans shook his head, dismayed. No, he really hadn’t needed the king to find out that little issue of his.  
Still, Asgore pressed. “I need you. The kingdom needs you. You’re important, Sans.”  
Sans cried out, stopping his relentless humping to lean over, gasping. “My legs...I can’t move,” he confessed. He was trembling, covered in cyan sweat.  
Asgore hummed. “Of course.” He gathered Sans to his chest and rolled them over, never relieving Sans of the pressure. He braced his forearms on either side of the skeleton, gave him a glance, then began thrusting.  
It was like being hit with a piston. Sans almost screamed, clutching at Asgore’s arms helplessly as he was plowed. He sobbed, and heard Asgore’s unhappy grunt, but he just wrapped his legs around as much of the king’s waist as he could.  
“Fuck, fuck, it’s good,” he gasped out, trying to reassure him. “It’s good!”  
Asgore hesitated, but then continued. Sans had to give it to him, he had some insane control of his hips. Asgore was panting, eyes slightly closed as he reveled in the feeling of Sans’s tight body constricting around him. He pressed his forehead against Sans’s shoulder.  
Sans shuddered. “Please, I need...” he choked out. “Please touch me.”  
Asgore shifted his weight to one arm and reached between them to press against Sans’s clit.  
Sans wailed, overwhelmed. Asgore was surrounding him, inside him, and tearing both his body and his mind to pieces. It only took a couple strokes before he was coming again, back arching painfully as he did.  
He might have blacked out. Or whited out? Either way, when he came to, Asgore was staring at him with mild worry. He was still laying over him, arms braced. “Howdy,” he said, the pleasantry forced.  
Sans chuckled weakly. “Howdy.” He realized he was still connected to Asgore and blinked.  
The king huffed. “Oh, right.” He started to withdraw, Sans gasping at the pressure, but the judge grabbed hips with his legs.  
“You haven’t cum,” Sans said bluntly.  
Asgore shrugged. “It isn’t important.”  
“It is to me,” he retorted, a little frustrated. “Come on, kingy, just use me already. It’s fine.”  
Asgore winced at the phrasing, but seemed shamefully wanting. He gave Sans another look, judging his resolve, and started to push back in.  
It was slower this time, almost loving, as Asgore worked himself up. Sans’s magic dragged along his dick as he withdrew and pushed back in, his soaking cunt making loud slick noises in the room. He was pretty sure the bed was drenched.  
Asgore started grunting as he thrust, movements speeding up and becoming jerky. He gasped as he came, pushing his cock deep into Sans and going still.  
Sans shivered, clutching at the king. Asgore was pulsing inside him, shots of warm seed filling him up almost as much as his dick did. Sans tried to focus on breathing instead of losing himself in the sensation.  
After a pause, Asgore lifted himself up. He began pulling out, Sans moaning helplessly at the friction on his sensitive magic. Warmth flooded down him as Asgore withdrew, and Sans felt mixed blue and orange cum sliding out of him. He sucked in a breath, reaching between his legs to stick his fingers into the sticky mess.  
Asgore watched.  
Sans shivered again. It was a lot. Much more than his usual partners ejaculated. He drew his colorful fingers up to his mouth and licked it off, watching Asgore’s expression.  
Asgore huffed, smiling wryly. “I am willing to go around round, but I think you should sleep,” he said to the unspoken offer.  
Sans shrugged. “Could fuck me while I sleep, I wouldn’t be complaining.”  
Asgore chuckled. “You wouldn’t get much sleeping done.” He checked the clock on the nightstand by his bed. “You best take a nap and then head out, Sans. Your brother will be searching for you soon enough.”  
Sans winced. “Let’s not talk about Paps while your cum is still sliding out of me,” he griped.  
Asgore smiled. “Very well.” He picked Sans up again, ever so gentle, and laid on his back, settling the skeleton against his chest.  
Sans considered protesting, but the fur was very soft and warm. And he was tired. His magic wouldn’t dissipate for a bit, still too full of Asgore’s seed, so rest was probably in order anyway.  
As he laid his skull against Asgore’s chest, listening to his soul hum, he plotted ways to get back into the king’s bed next time.

**Author's Note:**

> List used: https://twitter.com/idek_uggy/status/1178349575725174786?s=21
> 
> Tomorrow is spitroasting!


End file.
